The primary objective of this study was to link the capabilities of a physically challenged person to his or her ability to perform activities of daily living, by studying how net joint moments and individual muscle forces contribute to the control of human movement. Measuring these contributions is critical for defining adaptive movement control strategies, understanding the process by which movement control strategies for activities like walking, standing and rising from a seated position are selected and implemented, and determining the contribution that assistive technologies play in enhancing function. We have extended existing movement analysis methodologies that estimate the influence of joint moments or muscle forces on the motion of individual joints and body segments, as well as their contribution to overall task performance.